Grace, I agree that trying a demonstrator before you buy is the best approach. One thing that you want to take into consideration besides the compression points that Bob mentioned is the harmonic / distortion requirements mentioned in section 6 of 61000-4-3. The 2006 version of IEC 61000-4-3 is a bit different than the current version of EN 61000-4-3. IEC 61000-4-3:2006 [expected to be published as EN this year] requires that harmonics in the uniform field area field be at least 6 dB below the fundamental. There is a lot of good info in Annex D about how to accomplish / measure this. The current EN 61000-4-3 requires that the amplifier not produce harmonics > 15 dB below carrier. Whichever amp you choose, make sure that you take these considerations into account as well. Good luck! Mac Elliott
_____ From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Mowbray, John H Sent: Thursday, June 08, 2006 3:56 PM To: Grace Lin; emc-p...@ieee.org Subject: RE: RF Power Amplifiers Grace For the 80-100 range the power sounds about right, but be careful many amplifiers will ouptut reduced power if the VSWR at their output exceeds 2:1. For the other ranges the 75 W should be more like 25-50 W, again depending on the amplifier and VSWR. The high frequency amplifier should be at least 30 W to account for the higher cable losses. The best approach is to try a demonstrator before you buy. I have seen amplifiers that would only produce 1/2 of their rated output power in my test setup. John Mowbray, P. Eng. Senior EMC Engineer NCR Canada, Ltd. 580 Weber St. N. Waterloo, Ontario N2J 4G5 519 884 1710 X5371 john.mowb...@ncr.com _____ From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Grace Lin Sent: June 8, 2006 3:24 PM To: emc-p...@ieee.org Subject: RF Power Amplifiers Dear Group Members, Please help me to determine specification for RF power amplifiers for 61000-4-3 and 61000-4-6 tests. I found an equation to calculate power required (ETS-Lindgren Antenna Catalog, page 71): PdB(W) = 20 log10 (Edesired(V/m)) +20 log10 (d m) – 20 log10 (fMHz) +AFdB(m-1) +15 Based on this equation, my calculated results are: For 10V/m @ 3m at 80MHz by using ETS-Lindgren 3149 antenna: P(W) = 111.7018 For 10V/m @ 3m at 80MHz by using Schaffner CBL 6140 antenna: P(W) = 22.2874 For 10V/m @ 3m at 1000MHz by using ETS-Lindgren 3149 antenna: P(W) = 12.0016 For 10V/m @ 3m at 1000MHz by using Schaffner CBL 6140 antenna: P(W) = 7.1489 For 10V/m @ 3m at 1GHz by using ETS-Lindgren 3115 antenna: P(W) = 7.1489 For 10V/m @ 3m at 4GHz by using ETS-Lindgren 3115 antenna: P(W) = 4.4681 Do these mean that a 150 watts amplifier is enough for the frequency range 80MHz-1000NHz, and a 10 watts' is enough for the frequency range 1-4GHz? Is a 75 watts' good enough for 61000-4-6 test? Is there any other factors, such as cable loss, etc., that I have to include in the calculation? The measuring system will include a dual directional coupler and a power meter. I have received different recommended specifications. Different specifications mean different prices. The price difference is huge between wattages. Your help is highly appreciated! Best regards, Grace Lin Crestron Electronics, Inc. New Jersey, USA www.crestron.com <http://www.crestron.com/> - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
